You will need to feed them locus and crickets and they should last up to 10 days then you can leave it for 4 days the refill. Thats what I do. But geckos can live up to 4 weeks without food.
It does depend on how old they are younger geckos can be fed small amount daily so they don't have to digest a large meal like maybe an adult gecko would, it does vary on the appetite of your gecko to as you get to know them . Mine eat every other day they have maybe 2 meal worms each and maybe 3 or 4 crickets they know when they have had enough and maybe one day in the week I will feed them wax worms as a treat maybe just 2 or 3 each and no crickets its all personal preference and what your geckos enjoy the most(usually wax worms! They are high in fat so not to many think of them as a bar of chocolate we love it but shouldnt eat it every day lol! Hope this helps.
When I feed my gecko, I give it 3 crickets then I'll feed it after 3 days.
How often should you feed a fat-tailed-gecko baby food????? I looked what to feed geckos and it said baby food is best, too.